At present, low-temperature polysilicon thin film transistors (LTPS TFTs) receive much attention for their high electron mobility and stability. Most of the traditional low-temperature polysilicon thin-film transistor using the top gate structure. However, the surface of the active layer deposited by deposition is not smooth, which may result in poor flatness of structures such as gates subsequently deposited on the active layer, the resistance distribution of the interface between the active layer and the gate is apt to be uneven, which leads to the instability of the overall performance.